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   1 /*
   2  *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  *
  26  * TBD:
  27  *      1. Support more than one IRQ resource entry per link device (index).
  28  *      2. Implement start/stop mechanism and use ACPI Bus Driver facilities
  29  *         for IRQ management (e.g. start()->_SRS).
  30  */
  31
  32 #include <linux/sysdev.h>
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/types.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/pm.h>
  40 #include <linux/pci.h>
  41
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44
  45
  46 #define _COMPONENT              ACPI_PCI_COMPONENT
  47 ACPI_MODULE_NAME                ("pci_link")
  48
  49 #define ACPI_PCI_LINK_CLASS             "pci_irq_routing"
  50 #define ACPI_PCI_LINK_HID               "PNP0C0F"
  51 #define ACPI_PCI_LINK_DRIVER_NAME       "ACPI PCI Interrupt Link Driver"
  52 #define ACPI_PCI_LINK_DEVICE_NAME       "PCI Interrupt Link"
  53 #define ACPI_PCI_LINK_FILE_INFO         "info"
  54 #define ACPI_PCI_LINK_FILE_STATUS       "state"
  55
  56 #define ACPI_PCI_LINK_MAX_POSSIBLE 16
  57
  58 static int acpi_pci_link_add (struct acpi_device *device);
  59 static int acpi_pci_link_remove (struct acpi_device *device, int type);
  60
  61 static struct acpi_driver acpi_pci_link_driver = {
  62         .name =         ACPI_PCI_LINK_DRIVER_NAME,
  63         .class =        ACPI_PCI_LINK_CLASS,
  64         .ids =          ACPI_PCI_LINK_HID,
  65         .ops =          {
  66                                 .add =    acpi_pci_link_add,
  67                                 .remove = acpi_pci_link_remove,
  68                         },
  69 };
  70
  71 /*
  72  * If a link is initialized, we never change its active and initialized
  73  * later even the link is disable. Instead, we just repick the active irq
  74  */
  75 struct acpi_pci_link_irq {
  76         u8                      active;                 /* Current IRQ */
  77         u8                      edge_level;             /* All IRQs */
  78         u8                      active_high_low;        /* All IRQs */
  79         u8                      resource_type;
  80         u8                      possible_count;
  81         u8                      possible[ACPI_PCI_LINK_MAX_POSSIBLE];
  82         u8                      initialized:1;
  83         u8                      reserved:7;
  84 };
  85
  86 struct acpi_pci_link {
  87         struct list_head        node;
  88         struct acpi_device      *device;
  89         acpi_handle             handle;
  90         struct acpi_pci_link_irq irq;
  91         int                     refcnt;
  92 };
  93
  94 static struct {
  95         int                     count;
  96         struct list_head        entries;
  97 }                               acpi_link;
  98 DECLARE_MUTEX(acpi_link_lock);
  99
 100
 101 /* --------------------------------------------------------------------------
 102                             PCI Link Device Management
 103    -------------------------------------------------------------------------- */
 104
 105 /*
 106  * set context (link) possible list from resource list
 107  */
 108 static acpi_status
 109 acpi_pci_link_check_possible (
 110         struct acpi_resource    *resource,
 111         void                    *context)
 112 {
 113         struct acpi_pci_link    *link = (struct acpi_pci_link *) context;
 114         u32                     i = 0;
 115
 116         ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
 117
 118         switch (resource->id) {
 119         case ACPI_RSTYPE_START_DPF:
 120                 return_ACPI_STATUS(AE_OK);
 121         case ACPI_RSTYPE_IRQ:
 122         {
 123                 struct acpi_resource_irq *p = &resource->data.irq;
 124                 if (!p || !p->number_of_interrupts) {
 125                         ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Blank IRQ resource\n"));
 126                         return_ACPI_STATUS(AE_OK);
 127                 }
 128                 for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 129                         if (!p->interrupts[i]) {
 130                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 131                                 continue;
 132                         }
 133                         link->irq.possible[i] = p->interrupts[i];
 134                         link->irq.possible_count++;
 135                 }
 136                 link->irq.edge_level = p->edge_level;
 137                 link->irq.active_high_low = p->active_high_low;
 138                 link->irq.resource_type = ACPI_RSTYPE_IRQ;
 139                 break;
 140         }
 141         case ACPI_RSTYPE_EXT_IRQ:
 142         {
 143                 struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 144                 if (!p || !p->number_of_interrupts) {
 145                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 146                                 "Blank EXT IRQ resource\n"));
 147                         return_ACPI_STATUS(AE_OK);
 148                 }
 149                 for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
 150                         if (!p->interrupts[i]) {
 151                                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
 152                                 continue;
 153                         }
 154                         link->irq.possible[i] = p->interrupts[i];
 155                         link->irq.possible_count++;
 156                 }
 157                 link->irq.edge_level = p->edge_level;
 158                 link->irq.active_high_low = p->active_high_low;
 159                 link->irq.resource_type = ACPI_RSTYPE_EXT_IRQ;
 160                 break;
 161         }
 162         default:
 163                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 164                         "Resource is not an IRQ entry\n"));
 165                 return_ACPI_STATUS(AE_OK);
 166         }
 167
 168         return_ACPI_STATUS(AE_CTRL_TERMINATE);
 169 }
 170
 171
 172 static int
 173 acpi_pci_link_get_possible (
 174         struct acpi_pci_link    *link)
 175 {
 176         acpi_status             status;
 177
 178         ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
 179
 180         if (!link)
 181                 return_VALUE(-EINVAL);
 182
 183         status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
 184                         acpi_pci_link_check_possible, link);
 185         if (ACPI_FAILURE(status)) {
 186                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
 187                 return_VALUE(-ENODEV);
 188         }
 189
 190         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 191                 "Found %d possible IRQs\n", link->irq.possible_count));
 192
 193         return_VALUE(0);
 194 }
 195
 196
 197 static acpi_status
 198 acpi_pci_link_check_current (
 199         struct acpi_resource    *resource,
 200         void                    *context)
 201 {
 202         int                     *irq = (int *) context;
 203
 204         ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
 205
 206         switch (resource->id) {
 207         case ACPI_RSTYPE_IRQ:
 208         {
 209                 struct acpi_resource_irq *p = &resource->data.irq;
 210                 if (!p || !p->number_of_interrupts) {
 211                         /*
 212                          * IRQ descriptors may have no IRQ# bits set,
 213                          * particularly those those w/ _STA disabled
 214                          */
 215                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 216                                 "Blank IRQ resource\n"));
 217                         return_ACPI_STATUS(AE_OK);
 218                 }
 219                 *irq = p->interrupts[0];
 220                 break;
 221         }
 222         case ACPI_RSTYPE_EXT_IRQ:
 223         {
 224                 struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
 225                 if (!p || !p->number_of_interrupts) {
 226                         /*
 227                          * extended IRQ descriptors must
 228                          * return at least 1 IRQ
 229                          */
 230                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 231                                 "Blank EXT IRQ resource\n"));
 232                         return_ACPI_STATUS(AE_OK);
 233                 }
 234                 *irq = p->interrupts[0];
 235                 break;
 236         }
 237         default:
 238                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 239                         "Resource isn't an IRQ\n"));
 240                 return_ACPI_STATUS(AE_OK);
 241         }
 242         return_ACPI_STATUS(AE_CTRL_TERMINATE);
 243 }
 244
 245 /*
 246  * Run _CRS and set link->irq.active
 247  *
 248  * return value:
 249  * 0 - success
 250  * !0 - failure
 251  */
 252 static int
 253 acpi_pci_link_get_current (
 254         struct acpi_pci_link    *link)
 255 {
 256         int                     result = 0;
 257         acpi_status             status = AE_OK;
 258         int                     irq = 0;
 259
 260         ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
 261
 262         if (!link || !link->handle)
 263                 return_VALUE(-EINVAL);
 264
 265         link->irq.active = 0;
 266
 267         /* in practice, status disabled is meaningless, ignore it */
 268         if (acpi_strict) {
 269                 /* Query _STA, set link->device->status */
 270                 result = acpi_bus_get_status(link->device);
 271                 if (result) {
 272                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 273                         goto end;
 274                 }
 275
 276                 if (!link->device->status.enabled) {
 277                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
 278                         return_VALUE(0);
 279                 }
 280         }
 281
 282         /*
 283          * Query and parse _CRS to get the current IRQ assignment.
 284          */
 285
 286         status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
 287                         acpi_pci_link_check_current, &irq);
 288         if (ACPI_FAILURE(status)) {
 289                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
 290                 result = -ENODEV;
 291                 goto end;
 292         }
 293
 294         if (acpi_strict && !irq) {
 295                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
 296                 result = -ENODEV;
 297         }
 298
 299         link->irq.active = irq;
 300
 301         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
 302
 303 end:
 304         return_VALUE(result);
 305 }
 306
 307 static int
 308 acpi_pci_link_set (
 309         struct acpi_pci_link    *link,
 310         int                     irq)
 311 {
 312         int                     result = 0;
 313         acpi_status             status = AE_OK;
 314         struct {
 315                 struct acpi_resource    res;
 316                 struct acpi_resource    end;
 317         }    *resource;
 318         struct acpi_buffer      buffer = {0, NULL};
 319
 320         ACPI_FUNCTION_TRACE("acpi_pci_link_set");
 321
 322         if (!link || !irq)
 323                 return_VALUE(-EINVAL);
 324
 325         resource = kmalloc( sizeof(*resource)+1, GFP_KERNEL);
 326         if(!resource)
 327                 return_VALUE(-ENOMEM);
 328
 329         memset(resource, 0, sizeof(*resource)+1);
 330         buffer.length = sizeof(*resource) +1;
 331         buffer.pointer = resource;
 332
 333         switch(link->irq.resource_type) {
 334         case ACPI_RSTYPE_IRQ:
 335                 resource->res.id = ACPI_RSTYPE_IRQ;
 336                 resource->res.length = sizeof(struct acpi_resource);
 337                 resource->res.data.irq.edge_level = link->irq.edge_level;
 338                 resource->res.data.irq.active_high_low = link->irq.active_high_low;
 339                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 340                         resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 341                 else
 342                         resource->res.data.irq.shared_exclusive = ACPI_SHARED;
 343                 resource->res.data.irq.number_of_interrupts = 1;
 344                 resource->res.data.irq.interrupts[0] = irq;
 345                 break;
 346
 347         case ACPI_RSTYPE_EXT_IRQ:
 348                 resource->res.id = ACPI_RSTYPE_EXT_IRQ;
 349                 resource->res.length = sizeof(struct acpi_resource);
 350                 resource->res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
 351                 resource->res.data.extended_irq.edge_level = link->irq.edge_level;
 352                 resource->res.data.extended_irq.active_high_low = link->irq.active_high_low;
 353                 if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
 354                         resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
 355                 else
 356                         resource->res.data.irq.shared_exclusive = ACPI_SHARED;
 357                 resource->res.data.extended_irq.number_of_interrupts = 1;
 358                 resource->res.data.extended_irq.interrupts[0] = irq;
 359                 /* ignore resource_source, it's optional */
 360                 break;
 361         default:
 362                 printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
 363                 result = -EINVAL;
 364                 goto end;
 365
 366         }
 367         resource->end.id = ACPI_RSTYPE_END_TAG;
 368
 369         /* Attempt to set the resource */
 370         status = acpi_set_current_resources(link->handle, &buffer);
 371
 372         /* check for total failure */
 373         if (ACPI_FAILURE(status)) {
 374                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
 375                 result = -ENODEV;
 376                 goto end;
 377         }
 378
 379         /* Query _STA, set device->status */
 380         result = acpi_bus_get_status(link->device);
 381         if (result) {
 382                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
 383                 goto end;
 384         }
 385         if (!link->device->status.enabled) {
 386                 printk(KERN_WARNING PREFIX
 387                         "%s [%s] disabled and referenced, BIOS bug.\n",
 388                         acpi_device_name(link->device),
 389                         acpi_device_bid(link->device));
 390         }
 391
 392         /* Query _CRS, set link->irq.active */
 393         result = acpi_pci_link_get_current(link);
 394         if (result) {
 395                 goto end;
 396         }
 397
 398         /*
 399          * Is current setting not what we set?
 400          * set link->irq.active
 401          */
 402         if (link->irq.active != irq) {
 403                 /*
 404                  * policy: when _CRS doesn't return what we just _SRS
 405                  * assume _SRS worked and override _CRS value.
 406                  */
 407                 printk(KERN_WARNING PREFIX
 408                         "%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
 409                         acpi_device_name(link->device),
 410                         acpi_device_bid(link->device),
 411                         link->irq.active, irq);
 412                 link->irq.active = irq;
 413         }
 414
 415         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
 416
 417 end:
 418         kfree(resource);
 419         return_VALUE(result);
 420 }
 421
 422
 423 /* --------------------------------------------------------------------------
 424                             PCI Link IRQ Management
 425    -------------------------------------------------------------------------- */
 426
 427 /*
 428  * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
 429  * Link Devices to move the PIRQs around to minimize sharing.
 430  *
 431  * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
 432  * that the BIOS has already set to active.  This is necessary because
 433  * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
 434  * if the BIOS doesn't set a Link Device active, ACPI needs to program it
 435  * even if acpi_irq_nobalance is set.
 436  *
 437  * A tables of penalties avoids directing PCI interrupts to well known
 438  * ISA IRQs. Boot params are available to over-ride the default table:
 439  *
 440  * List interrupts that are free for PCI use.
 441  * acpi_irq_pci=n[,m]
 442  *
 443  * List interrupts that should not be used for PCI:
 444  * acpi_irq_isa=n[,m]
 445  *
 446  * Note that PCI IRQ routers have a list of possible IRQs,
 447  * which may not include the IRQs this table says are available.
 448  *
 449  * Since this heuristic can't tell the difference between a link
 450  * that no device will attach to, vs. a link which may be shared
 451  * by multiple active devices -- it is not optimal.
 452  *
 453  * If interrupt performance is that important, get an IO-APIC system
 454  * with a pin dedicated to each device.  Or for that matter, an MSI
 455  * enabled system.
 456  */
 457
 458 #define ACPI_MAX_IRQS           256
 459 #define ACPI_MAX_ISA_IRQ        16
 460
 461 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
 462 #define PIRQ_PENALTY_PCI_POSSIBLE       (16*16)
 463 #define PIRQ_PENALTY_PCI_USING          (16*16*16)
 464 #define PIRQ_PENALTY_ISA_TYPICAL        (16*16*16*16)
 465 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 466 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 467
 468 static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
 469         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
 470         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
 471         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
 472         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ3 serial */
 473         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ4 serial */
 474         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ5 sometimes SoundBlaster */
 475         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
 476         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
 477         PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
 478         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
 479         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
 480         PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
 481         PIRQ_PENALTY_ISA_USED,  /* IRQ12 mouse */
 482         PIRQ_PENALTY_ISA_USED,  /* IRQ13 fpe, sometimes */
 483         PIRQ_PENALTY_ISA_USED,  /* IRQ14 ide0 */
 484         PIRQ_PENALTY_ISA_USED,  /* IRQ15 ide1 */
 485                         /* >IRQ15 */
 486 };
 487
 488 int __init
 489 acpi_irq_penalty_init(void)
 490 {
 491         struct list_head        *node = NULL;
 492         struct acpi_pci_link    *link = NULL;
 493         int                     i = 0;
 494
 495         ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
 496
 497         /*
 498          * Update penalties to facilitate IRQ balancing.
 499          */
 500         list_for_each(node, &acpi_link.entries) {
 501
 502                 link = list_entry(node, struct acpi_pci_link, node);
 503                 if (!link) {
 504                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 505                         continue;
 506                 }
 507
 508                 /*
 509                  * reflect the possible and active irqs in the penalty table --
 510                  * useful for breaking ties.
 511                  */
 512                 if (link->irq.possible_count) {
 513                         int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;
 514
 515                         for (i = 0; i < link->irq.possible_count; i++) {
 516                                 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
 517                                         acpi_irq_penalty[link->irq.possible[i]] += penalty;
 518                         }
 519
 520                 } else if (link->irq.active) {
 521                         acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
 522                 }
 523         }
 524         /* Add a penalty for the SCI */
 525         acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
 526
 527         return_VALUE(0);
 528 }
 529
 530 static int acpi_irq_balance;    /* 0: static, 1: balance */
 531
 532 static int acpi_pci_link_allocate(
 533         struct acpi_pci_link    *link)
 534 {
 535         int                     irq;
 536         int                     i;
 537
 538         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 539
 540         if (link->irq.initialized) {
 541                 if (link->refcnt == 0)
 542                         /* This means the link is disabled but initialized */
 543                         acpi_pci_link_set(link, link->irq.active);
 544                 return_VALUE(0);
 545         }
 546
 547         /*
 548          * search for active IRQ in list of possible IRQs.
 549          */
 550         for (i = 0; i < link->irq.possible_count; ++i) {
 551                 if (link->irq.active == link->irq.possible[i])
 552                         break;
 553         }
 554         /*
 555          * forget active IRQ that is not in possible list
 556          */
 557         if (i == link->irq.possible_count) {
 558                 if (acpi_strict)
 559                         printk(KERN_WARNING PREFIX "_CRS %d not found"
 560                                 " in _PRS\n", link->irq.active);
 561                 link->irq.active = 0;
 562         }
 563
 564         /*
 565          * if active found, use it; else pick entry from end of possible list.
 566          */
 567         if (link->irq.active) {
 568                 irq = link->irq.active;
 569         } else {
 570                 irq = link->irq.possible[link->irq.possible_count - 1];
 571         }
 572
 573         if (acpi_irq_balance || !link->irq.active) {
 574                 /*
 575                  * Select the best IRQ.  This is done in reverse to promote
 576                  * the use of IRQs 9, 10, 11, and >15.
 577                  */
 578                 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
 579                         if (acpi_irq_penalty[irq] > acpi_irq_penalty[link->irq.possible[i]])
 580                                 irq = link->irq.possible[i];
 581                 }
 582         }
 583
 584         /* Attempt to enable the link device at this IRQ. */
 585         if (acpi_pci_link_set(link, irq)) {
 586                 printk(PREFIX "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
 587                                 "Try pci=noacpi or acpi=off\n",
 588                         acpi_device_name(link->device),
 589                         acpi_device_bid(link->device));
 590                 return_VALUE(-ENODEV);
 591         } else {
 592                 acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
 593                 printk(PREFIX "%s [%s] enabled at IRQ %d\n",
 594                         acpi_device_name(link->device),
 595                         acpi_device_bid(link->device), link->irq.active);
 596         }
 597
 598         link->irq.initialized = 1;
 599
 600         return_VALUE(0);
 601 }
 602
 603 /*
 604  * acpi_pci_link_allocate_irq
 605  * success: return IRQ >= 0
 606  * failure: return -1
 607  */
 608
 609 int
 610 acpi_pci_link_allocate_irq (
 611         acpi_handle             handle,
 612         int                     index,
 613         int                     *edge_level,
 614         int                     *active_high_low,
 615         char                    **name)
 616 {
 617         int                     result = 0;
 618         struct acpi_device      *device = NULL;
 619         struct acpi_pci_link    *link = NULL;
 620
 621         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate_irq");
 622
 623         result = acpi_bus_get_device(handle, &device);
 624         if (result) {
 625                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 626                 return_VALUE(-1);
 627         }
 628
 629         link = (struct acpi_pci_link *) acpi_driver_data(device);
 630         if (!link) {
 631                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 632                 return_VALUE(-1);
 633         }
 634
 635         /* TBD: Support multiple index (IRQ) entries per Link Device */
 636         if (index) {
 637                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
 638                 return_VALUE(-1);
 639         }
 640
 641         down(&acpi_link_lock);
 642         if (acpi_pci_link_allocate(link)) {
 643                 up(&acpi_link_lock);
 644                 return_VALUE(-1);
 645         }
 646
 647         if (!link->irq.active) {
 648                 up(&acpi_link_lock);
 649                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
 650                 return_VALUE(-1);
 651         }
 652         link->refcnt ++;
 653         up(&acpi_link_lock);
 654
 655         if (edge_level) *edge_level = link->irq.edge_level;
 656         if (active_high_low) *active_high_low = link->irq.active_high_low;
 657         if (name) *name = acpi_device_bid(link->device);
 658         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 659                 "Link %s is referenced\n", acpi_device_bid(link->device)));
 660         return_VALUE(link->irq.active);
 661 }
 662
 663 /*
 664  * We don't change link's irq information here.  After it is reenabled, we
 665  * continue use the info
 666  */
 667 int
 668 acpi_pci_link_free_irq(acpi_handle handle)
 669 {
 670         struct acpi_device      *device = NULL;
 671         struct acpi_pci_link    *link = NULL;
 672         acpi_status             result;
 673
 674         ACPI_FUNCTION_TRACE("acpi_pci_link_free_irq");
 675
 676         result = acpi_bus_get_device(handle, &device);
 677         if (result) {
 678                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
 679                 return_VALUE(-1);
 680         }
 681
 682         link = (struct acpi_pci_link *) acpi_driver_data(device);
 683         if (!link) {
 684                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
 685                 return_VALUE(-1);
 686         }
 687
 688         down(&acpi_link_lock);
 689         if (!link->irq.initialized) {
 690                 up(&acpi_link_lock);
 691                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link isn't initialized\n"));
 692                 return_VALUE(-1);
 693         }
 694
 695 #ifdef  FUTURE_USE
 696         /*
 697          * The Link reference count allows us to _DISable an unused link
 698          * and suspend time, and set it again  on resume.
 699          * However, 2.6.12 still has irq_router.resume
 700          * which blindly restores the link state.
 701          * So we disable the reference count method
 702          * to prevent duplicate acpi_pci_link_set()
 703          * which would harm some systems
 704          */
 705         link->refcnt --;
 706 #endif
 707         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 708                 "Link %s is dereferenced\n", acpi_device_bid(link->device)));
 709
 710         if (link->refcnt == 0) {
 711                 acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 712         }
 713         up(&acpi_link_lock);
 714         return_VALUE(link->irq.active);
 715 }
 716 /* --------------------------------------------------------------------------
 717                                  Driver Interface
 718    -------------------------------------------------------------------------- */
 719
 720 static int
 721 acpi_pci_link_add (
 722         struct acpi_device *device)
 723 {
 724         int                     result = 0;
 725         struct acpi_pci_link    *link = NULL;
 726         int                     i = 0;
 727         int                     found = 0;
 728
 729         ACPI_FUNCTION_TRACE("acpi_pci_link_add");
 730
 731         if (!device)
 732                 return_VALUE(-EINVAL);
 733
 734         link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
 735         if (!link)
 736                 return_VALUE(-ENOMEM);
 737         memset(link, 0, sizeof(struct acpi_pci_link));
 738
 739         link->device = device;
 740         link->handle = device->handle;
 741         strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
 742         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
 743         acpi_driver_data(device) = link;
 744
 745         down(&acpi_link_lock);
 746         result = acpi_pci_link_get_possible(link);
 747         if (result)
 748                 goto end;
 749
 750         /* query and set link->irq.active */
 751         acpi_pci_link_get_current(link);
 752
 753         printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
 754                 acpi_device_bid(device));
 755         for (i = 0; i < link->irq.possible_count; i++) {
 756                 if (link->irq.active == link->irq.possible[i]) {
 757                         printk(" *%d", link->irq.possible[i]);
 758                         found = 1;
 759                 }
 760                 else
 761                         printk(" %d", link->irq.possible[i]);
 762         }
 763
 764         printk(")");
 765
 766         if (!found)
 767                 printk(" *%d", link->irq.active);
 768
 769         if(!link->device->status.enabled)
 770                 printk(", disabled.");
 771
 772         printk("\n");
 773
 774         /* TBD: Acquire/release lock */
 775         list_add_tail(&link->node, &acpi_link.entries);
 776         acpi_link.count++;
 777
 778 end:
 779         /* disable all links -- to be activated on use */
 780         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
 781         up(&acpi_link_lock);
 782
 783         if (result)
 784                 kfree(link);
 785
 786         return_VALUE(result);
 787 }
 788
 789 static int
 790 acpi_pci_link_resume(
 791         struct acpi_pci_link *link)
 792 {
 793         ACPI_FUNCTION_TRACE("acpi_pci_link_resume");
 794
 795         if (link->refcnt && link->irq.active && link->irq.initialized)
 796                 return_VALUE(acpi_pci_link_set(link, link->irq.active));
 797         else
 798                 return_VALUE(0);
 799 }
 800
 801 /*
 802  * FIXME: this is a workaround to avoid nasty warning.  It will be removed
 803  * after every device calls pci_disable_device in .resume.
 804  */
 805 int acpi_in_resume;
 806 static int
 807 irqrouter_resume(
 808         struct sys_device *dev)
 809 {
 810         struct list_head        *node = NULL;
 811         struct acpi_pci_link    *link = NULL;
 812
 813         ACPI_FUNCTION_TRACE("irqrouter_resume");
 814
 815         acpi_in_resume = 1;
 816         list_for_each(node, &acpi_link.entries) {
 817                 link = list_entry(node, struct acpi_pci_link, node);
 818                 if (!link) {
 819                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 820                                 "Invalid link context\n"));
 821                         continue;
 822                 }
 823                 acpi_pci_link_resume(link);
 824         }
 825         acpi_in_resume = 0;
 826         return_VALUE(0);
 827 }
 828
 829
 830 static int
 831 acpi_pci_link_remove (
 832         struct acpi_device      *device,
 833         int                     type)
 834 {
 835         struct acpi_pci_link *link = NULL;
 836
 837         ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
 838
 839         if (!device || !acpi_driver_data(device))
 840                 return_VALUE(-EINVAL);
 841
 842         link = (struct acpi_pci_link *) acpi_driver_data(device);
 843
 844         down(&acpi_link_lock);
 845         list_del(&link->node);
 846         up(&acpi_link_lock);
 847
 848         kfree(link);
 849
 850         return_VALUE(0);
 851 }
 852
 853 /*
 854  * modify acpi_irq_penalty[] from cmdline
 855  */
 856 static int __init acpi_irq_penalty_update(char *str, int used)
 857 {
 858         int i;
 859
 860         for (i = 0; i < 16; i++) {
 861                 int retval;
 862                 int irq;
 863
 864                 retval = get_option(&str,&irq);
 865
 866                 if (!retval)
 867                         break;  /* no number found */
 868
 869                 if (irq < 0)
 870                         continue;
 871
 872                 if (irq >= ACPI_MAX_IRQS)
 873                         continue;
 874
 875                 if (used)
 876                         acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 877                 else
 878                         acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 879
 880                 if (retval != 2)        /* no next number */
 881                         break;
 882         }
 883         return 1;
 884 }
 885
 886 /*
 887  * We'd like PNP to call this routine for the
 888  * single ISA_USED value for each legacy device.
 889  * But instead it calls us with each POSSIBLE setting.
 890  * There is no ISA_POSSIBLE weight, so we simply use
 891  * the (small) PCI_USING penalty.
 892  */
 893 void acpi_penalize_isa_irq(int irq, int active)
 894 {
 895         if (active)
 896                 acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
 897         else
 898                 acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
 899 }
 900
 901 /*
 902  * Over-ride default table to reserve additional IRQs for use by ISA
 903  * e.g. acpi_irq_isa=5
 904  * Useful for telling ACPI how not to interfere with your ISA sound card.
 905  */
 906 static int __init acpi_irq_isa(char *str)
 907 {
 908         return acpi_irq_penalty_update(str, 1);
 909 }
 910 __setup("acpi_irq_isa=", acpi_irq_isa);
 911
 912 /*
 913  * Over-ride default table to free additional IRQs for use by PCI
 914  * e.g. acpi_irq_pci=7,15
 915  * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
 916  */
 917 static int __init acpi_irq_pci(char *str)
 918 {
 919         return acpi_irq_penalty_update(str, 0);
 920 }
 921 __setup("acpi_irq_pci=", acpi_irq_pci);
 922
 923 static int __init acpi_irq_nobalance_set(char *str)
 924 {
 925         acpi_irq_balance = 0;
 926         return 1;
 927 }
 928 __setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
 929
 930 int __init acpi_irq_balance_set(char *str)
 931 {
 932         acpi_irq_balance = 1;
 933         return 1;
 934 }
 935 __setup("acpi_irq_balance", acpi_irq_balance_set);
 936
 937
 938 /* FIXME: we will remove this interface after all drivers call pci_disable_device */
 939 static struct sysdev_class irqrouter_sysdev_class = {
 940         set_kset_name("irqrouter"),
 941         .resume = irqrouter_resume,
 942 };
 943
 944
 945 static struct sys_device device_irqrouter = {
 946         .id     = 0,
 947         .cls    = &irqrouter_sysdev_class,
 948 };
 949
 950
 951 static int __init irqrouter_init_sysfs(void)
 952 {
 953         int error;
 954
 955         ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");
 956
 957         if (acpi_disabled || acpi_noirq)
 958                 return_VALUE(0);
 959
 960         error = sysdev_class_register(&irqrouter_sysdev_class);
 961         if (!error)
 962                 error = sysdev_register(&device_irqrouter);
 963
 964         return_VALUE(error);
 965 }
 966
 967 device_initcall(irqrouter_init_sysfs);
 968
 969
 970 static int __init acpi_pci_link_init (void)
 971 {
 972         ACPI_FUNCTION_TRACE("acpi_pci_link_init");
 973
 974         if (acpi_noirq)
 975                 return_VALUE(0);
 976
 977         acpi_link.count = 0;
 978         INIT_LIST_HEAD(&acpi_link.entries);
 979
 980         if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
 981                 return_VALUE(-ENODEV);
 982
 983         return_VALUE(0);
 984 }
 985
 986 subsys_initcall(acpi_pci_link_init);